CVE-2017-5447

CRITICAL

Debian Linux < 45.9.0 - Use After Free

Title source: rule
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2017-5447. PoCs published by Google Security Research.

AI-analyzed exploit summary This exploit demonstrates an out-of-bounds read vulnerability in Firefox (CVE-2017-5447) by manipulating DOM elements and CSS properties to trigger a heap-buffer-overflow. The PoC uses a combination of JavaScript and HTML to force the browser into an unstable state, as confirmed by the AddressSanitizer (ASan) log.

Description

An out-of-bounds read during the processing of glyph widths during text layout. This results in a potentially exploitable crash and could allow an attacker to read otherwise inaccessible memory. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Exploits (1)

exploitdb WORKING POC VERIFIED
by Google Security Research · htmldosmultiple
https://www.exploit-db.com/exploits/42071

This exploit demonstrates an out-of-bounds read vulnerability in Firefox (CVE-2017-5447) by manipulating DOM elements and CSS properties to trigger a heap-buffer-overflow. The PoC uses a combination of JavaScript and HTML to force the browser into an unstable state, as confirmed by the AddressSanitizer (ASan) log.

Classification
Working Poc 90%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Mozilla Firefox (Nightly ASan build, confirmed in bug report)
No auth needed
Prerequisites: Victim must visit a malicious webpage or open a crafted HTML file
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (12)

Core 12
Core References
Exploit, Third Party Advisory, VDB Entry exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/42071/
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2017:1106
Exploit, Issue Tracking, Vendor Advisory x_refsource_confirm
https://bugzilla.mozilla.org/show_bug.cgi?id=1343552
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2017-12/
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2017-11/
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2017-10/
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/97940
Third Party Advisory vendor-advisory x_refsource_debian
https://www.debian.org/security/2017/dsa-3831
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2017-13/
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1038320
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2017:1104
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2017:1201

Scores

CVSS v3 9.1
EPSS 0.1098
EPSS Percentile 93.6%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Details

CWE
CWE-416
Status published
Products (17)
debian/debian_linux 9.0
mozilla/firefox 52.0
mozilla/firefox < 45.9.0
mozilla/thunderbird < 52.1.0
redhat/enterprise_linux 6.0
redhat/enterprise_linux 7.0
redhat/enterprise_linux_desktop 6.0
redhat/enterprise_linux_desktop 7.0
redhat/enterprise_linux_server 6.0
redhat/enterprise_linux_server 7.0
... and 7 more
Published Jun 11, 2018
Tracked Since Feb 18, 2026